A well-known conventional bicycle saddle is such that a saddle main body is constituted with a base member composed of a hard synthetic resin material, a cushion sheet composed of urethane or the like high in flexibility which is laminated on an upper face thereof, and an exterior sheet which is laminated on the upper face of the cushion sheet to cover the base member in its entirety. (For example, see Patent literature 1)
Since the base member is injection-molded from a hard synthetic resin material high in rigidity so as to stably support the load of a rider, it is poor in flexibility and makes the buttocks sore etc., when the rider takes a ride, thereby posing a problem in terms of comfort. Thus, the cushion sheet high in flexibility is overlaid on an upper face of the base member to impart appropriate cushioning properties, thereby improving comfort.
However, in the case of the above-described bicycle saddle, the cushion sheet is covered with an exterior sheet which is thin and soft for attaining cushioning properties. Therefore, the cushion sheet is easily broken and comes out of the surface when, for example, a bicycle falls down, which poses a problem. Further, where the exterior sheet is broken off or not sufficiently water-proofed, rainwater easily seeps into the saddle on a rainy day, which also poses a problem. Still further, there is a problem that a saddle main body cannot be washed as it is.
Under these circumstances, there has been proposed a bicycle saddle which is made of a synthetic-resin base member having many through holes so that a saddle main body is able to undergo elastic deformation according to a change in load. (See Patent literature 2, 3)
In the above-described bicycle saddle, many through holes are formed so that the base member is able to easily undergo elastic deformation. Therefore, when the load of a rider is applied thereto, the base member receives the load, while slowly undergoing elastic deformation. As a result, use of only the base member is able to give appropriate cushioning properties to the saddle main body. Unlike a conventional case, it is not necessary to laminate a cushion sheet on an upper face of the base member, and when the bicycle saddle gets wet on a rainy day, rainwater on the base member can be wiped off to easily remove water. Thus, there is no discomfort due to rainwater seeping out from the cushion sheet when a rider takes a ride, as found in a conventional bicycle saddle. Further, the through holes formed on the base member are used to adjust cushioning properties of individual parts of the base member by combining a position of a through hole formed, a size, a shape, the number of the through holes, etc.
However, since the base member is formed with a single synthetic resin material, it has been difficult to balance contrasting elements such as flexibility/comfort and strength/rigidity only by combining a position of a through hole formed, a size, a shape, the number of the through holes, etc.
Therefore, a bicycle saddle disclosed in Patent Document 3 is provided with a flexible shock-absorbing material which is overlaid on the surface of a base member and able to quickly conform to the shape of the buttocks of a rider, softly receive the force acting on the buttocks by alleviating the force, thereby improving the flexibility/comfort.
Further, the bicycle saddle of Patent Document 3 is provided with a rigidity adjustor which is overlaid on the surface of the base member or filled into a through hole of the base member, thereby increasing the structural strength of the base member to improve the strength/rigidity of a saddle main body.
More specifically, the shock-absorbing material and the rigidity adjustor are provided as a seat which is overlaid on the base member in its entirety or in part or as a pad which is filled into a through hole of the base member.